Pune's elevated position on the Deccan Plateau gives it a more temperate climate than much of India, but the seasons still matter.
October to February is the best time to visit. Daytime temperatures hover around 25-30°C (77-86°F), nights can drop to 10-12°C (50-54°F), and the air is dry and clear. December and January are the coolest months -- you will want a light jacket for evenings. This is also the season for the Sawai Gandharva classical music festival and pleasant conditions for fort treks.
March to May gets progressively hotter, with temperatures reaching 38-40°C (100-104°F) in April and May. The city empties out as anyone who can heads to hill stations. However, May brings dramatic pre-monsoon thunderstorms that cool things down temporarily and provide spectacular sunsets.
June to September is the monsoon season. Pune receives moderate rainfall -- less than the coast but enough to turn the Sahyadri hills a vivid green. The hill stations of Lonavala and Khandala are at their most beautiful during and just after the rains, with waterfalls everywhere. Roads can be tricky, especially to forts and remote areas, and landslides occasionally close the Mumbai-Pune expressway. If you do not mind getting wet, the monsoon has its own appeal.
August-September brings Ganesh Chaturthi, Pune's biggest festival. The city is packed and accommodation fills up well in advance, but the atmosphere is unforgettable. Book early if you want to experience it.
Pune's altitude means the sun is strong year-round, even when temperatures are comfortable. Use sunscreen and stay hydrated regardless of the season.